2014 Third GENI Research and Educational Experiment Workshop
Embedding Switch Number, Port Number, and MAC Address (ESPM) within the IPv6 Address Bahaa Araji and Deniz Gurkan Computer Engineering Technology University of Houston Houston TX 77204
[email protected] We proposed to embed network topology information (e.g., switch ports, port number, MAC address) into the IPv6 address of a host to eliminate broadcasting and reduce the number of network management messages on the network.
Abstract— IPv4 protocol, the famous 32-bit address, has been used in networks for many decades [1] and would not have sustained its usability without NAT. IPv6 protocol with its 128bit address, provides slight routing information [2]. In this paper, we present ESPM, Embedding Switch ID, Port number and MAC Address within IPv6 protocol and SDN technology, imposing a device connectivity hierarchy upon the address space. We amend the IPv6 global addressing scheme for hosts to include their MAC address as well as the switch ID and Switch port number that they are connected to. This scheme encodes information that would ordinarily require a lookup or query packets(ARP) and decrease CAM table entries on the switch by forwarding the packets using the ESPM algorithm. After processing ESPM algorithm to check for OF controller ID, OF switch ID, and the port ID, the amount of total packets transferred on the network to fulfill an ICMP request-reply process decreased by 28.1% in 1-switch-2 hosts. In order to demonstrate the feasibility of such an addressing scheme, we use POF controller and POF switch [3] to emulate ESPM implementation and then measure the impact on the number of network management packets transferred between hosts during connectivity tests.
II.
ESPM ARCHITECTURE ELEMENTS
ESPM adopts the approach of dynamic host configuration protocol (DHCP) [7] and offers several advantages over regular dynamic addressing protocols. For example, it equips the addressing platform with data forwarding while dynamic addressing protocol just provides the logical information about the subnets used in the network. As soon as a host is connected to a switch port, a new IPv6 address is assigned according to OF switch ID, port ID, and the host MAC address. Each switch has a OF controller with a OF controller ID. The controller automatically and naturally determines the address of the host based on its location in the routing path: controller to switch, switch to port, and then port to host MAC. In this respect, an ESPM address “Fig.1,“ consists of (the assigned bit space here is given as an example):
Keywords – IPv6, SDN, OpenFlow, IP address, MAC address, DHCP, POForwarding, network addressing.
III. I.
INTRODUCTION
We implemented ESPM by utilizing the OpenFlow match fields that correspond to the destination IP address, input port, and MAC address “Fig.2,“. We assigned each host an IPv6 address within the ESPM scheme. Host A (MAC address:
ARP [4] is used to map the MAC address to a given IP address. ARP employs Ethertype 0x0806 and Ethernet broadcasting.. Processing ARP packets may consume a lot of processing power since all ARP requests are to be examined. In some operating systems processing ARP packets take priority over other activities.
Fig. 1. Example fields in the IPv6 represent site ID, controller ID, switch ID, port ID, and the MAC address.
Ethernet addresses do not allow implementation of prevention methods against loops [5]. Since spanning tree will force the network towards suboptimal routes, RSTP is usually disabled in DCs. Secondly, not only does Ethernet flood frames sent for unknown hosts, but it also employs and promotes higher-layer protocols to utilize broadcast as a means for control messages. For example, ARP executes address resolution via broadcast queries, and DHCP anticipates broadcast for automatic configuration. Broadcast traffic in normal conditions is (2%-5%) and should not exceed 20% of the total traffic to avoid broadcast storm and other network failures. It would be desirable for the network to minimize the amount of broadcast traffic. 978-1-4799-5120-8/14 $31.00 © 2014 IEEE DOI 10.1109/GREE.2014.20
IMPLEMENTATION ON GENI
1111.1111.1111) belongs to site ID=10, controller ID=1 and connects to switch ID=1 on port 1. Therefore, if we add the binary bits of all the five fields, we get the ESPM address for 69
host A (::A00:4000:402:2222:2222:2222), Host B will acquire an ESPM address in a similar way. In our implementation, we did a comparison between two networks regarding the number of packets exchanged during the ping process. The networks we used in the experiment are : x
POF Controller—POF Switch—Host A—Host B
x
Beacon Controller—OVS—Host A—Host B Fig.3. Manual counts of the packets exchanged during the ping process between Host A to Host B
V.
CONCLUSION AND FUTURE WORK
We implemented ESPM architecture on GENI testbed using the SDN experimentation capabilities. We loaded up the responsibility of parsing of header fields of IPv6 packets to a northbound application in order to setup reactive and proactive flows for IPv6 networks. GENI environment allowed us to test our location-based approach with programmable portability. Possible investigation points on GENI include: xMobility and host migration: Our strategy to deal with ESPM host migration is that on the arrival of the migrated host to the new switch, it will ask for an IPv6 address and the assigned IP address will be saved in the Controller. The controller will discover that the same physical MAC address acquiring two IPv6 addresses. To deal with this case, the controller will send a message to the old switch to redirect incoming traffic to the new switch until the CAM entry that corresponds to that host expires, then it will remove the old IPv6 address from its database
Fig.2 ESPM implementation
In the ESPM network, Host A pings Host B and destination IPv6 field inside the packet header will be analyzed by the ESPM code. Since the destination host acquires the same Site ID, Controller ID, Switch ID, the switch will find the port number that is embedded inside the ESPM address and forward the packet to that port. OpenFlow protocol will match the destination IPv6 address fields (with ESPM correspondence) to make a decision on the forwarding of the flows.
xScalability of the ESPM with many domains. References
IV. EVALUATION
[1] V. Cerf, and R. Kahn, “A Protocol for Packet Network intercommunication”, IEEE Transactions Communications, Vol. Corn-22, No. 5, May1974 pp. 637-648
With this implementation, we attempted a comparison of ESPM forwarding behavior using POForwarding to Ethernet forwarding manner in OpenFlow. In both networks, we produced real traffic using ping to send ICMP packets. We confirmed that packets were being sent to the exact host by using Wireshark software. We manually examined the packets over the network before and after enabling ESPM to find the benefits of the addressing scheme. The chart in “Fig.3,“ shows the decrease in total packets transferred to achieve ping between Host A and Host B by 28.1% .
[2] Deering, S. and R.Hinden,”Internet Protocol, Version 6 (IPv6) Specification”, RFC 2460, December 1998 http://tools.ietf.org/html/rfc2460 [3] H.Song “Protocol-Oblivious Forwarding: Unleash the Power of SDN through a Future-Proof Forwarding Plane “ [4] Plummer, D., "Ethernet Address Resolution Protocol: Orconverting network protocol addresses to 48.bit Ethernet address for transmission on Ethernet hardware", STD 37, RFC 826, November 1982 [5] R. M. Metcalfe and D. R. Boggs, “Ethernet: distributed packet switching for local computer networks,” ACM Communications, vol. 19, no. 7, pp. 395–404, 1976. [6] Perlman, Radia (1985). "An Algorithm for Distributed Computation of a Spanning Tree in an Extended LAN" [7] R. Droms, “Dynamic Host Configuration Protocol,”RFC 2131 (Draft Standard), Mar. 1997, updated by RFCs 3396, 4361.
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